In order to measure the position of a survey point or the like by using a conventional surveying instrument such as a total station (electric distance/angle meter), it was necessary to collimate a target placed at the survey point. In recent years, a surveying instrument having an automatic collimator has appeared on the market in order to reduce labor required to collimate a target and in order to reduce collimation errors committed by an operator. An automatic collimator is a device for determining the direction of a target by emitting a beam of collimation light along the collimation axis (optical axis) of a telescope of the surveying instrument and by receiving the collimation light reflected from the target so as to automatically and accurately direct the telescope toward the target. The surveying instrument having the thus structured automatic collimator has come to include a remote control device so that survey operations can be performed even by a single operator from a location away from the body of the surveying instrument.
However, a conventional problem resides in the fact that, when the surveying instrument having the automatic collimator or the surveying instrument having the remote control device performs a survey in accordance with a command emitted from the remote control device, the telescope must scan a wide range in order to set the target within a narrow visual field of the telescope, and hence much time is consumed for automatic collimation, and the survey cannot be smoothly performed.
To solve this problem, the present applicant has filed an application concerning a survey system according to which a target is swiftly found by emitting guide light from the target side, and time required for automatic collimation is shortened (see Patent Document 1 mentioned below). FIG. 8 to FIG. 10 show this survey system.
As shown in FIG. 8, the survey system is made up of a surveying instrument 50 having an automatic collimator and a target 60 having a reflecting prism (retro reflector) 62 that reflects rays of light in the direction of the incidence of the rays. The surveying instrument 50 has a horizontally rotatable instrument body 52 provided on a leveling plate (not shown) fixed onto a tripod 48 and a vertically rotatable telescope 54 provided in the instrument body 52. On a leveling plate 61 fixed onto a tripod 48, the target 60 has a reflecting prism 62 that reflects rays of collimation light 58 emitted from the surveying instrument 50 toward the surveying instrument 50 and a guide light transmitter 66 that emits rays of guide light 64 giving information about the direction of the target 60 toward the surveying instrument 50. The guide light 64 is modulated so that the surveying instrument 50 can recognize the guide light 64. Likewise, the collimation light 58 is modulated so that the surveying instrument 50 can recognize the collimation light 58.
The guide light transmitter 66 forms a wide fan beam that is vertically narrow and is horizontally wide. To form the fan beam, light emitted from a light source is diverged by a light transmitting lens that is a cylindrical lens. After that, the guide light transmitter 66 swings in the vertical direction and causes the guide light 64 to scan in the vertical direction.
The instrument body 52 of the surveying instrument 50 has a direction detector 56 that detects the direction of the guide light 64 emitted from the guide light transmitter 66. Since the guide light 64 scans in the vertical direction with a fan beam, the direction detector 56 can detect the direction of the guide light transmitter 66 even when a large difference in height lies between the surveying instrument 50 and the target 60 and even when these two elements do not exactly face each other.
The surveying instrument 50 and the target 60 have wireless devices 70 and 72, respectively, for transmitting command signals and survey results by radio 65 therebetween. The wireless devices 70 and 72 have non-directional antennas, respectively, so that communications can be exchanged even when the surveying instrument 50 and the target 60 do not substantially face each other, and the wireless devices 70 and 72 communicate with each other by radio waves 65.
Referring now to the block diagram of FIG. 9, a description will be given of the respective internal structures of the surveying instrument 50 and the target 60 that constitute the survey system.
The surveying instrument 50 includes a driving portion 101 that directs the telescope 54 toward the reflecting prism 62, a measuring portion 109 that measures a horizontal angle and a vertical angle of the telescope 54, a collimation light emitting portion 118 that emits collimation light 58 toward the reflecting prism 62, a collimation light receiver 120 that receives collimation light 58 reflected by the reflecting prism 62, a storage portion 122 that stores data such as measured angle values, a central processing unit (CPU) 100 connected to the driving portion 101, the collimation light emitting portion 118, the measuring portion 109, the collimation light receiver 120, and the storage portion 122, and a transmitted-light receiving portion (not shown) for calculating the distance between the reflecting prism 62 and the surveying instrument 50. Various commands and data can also be input from an operating/inputting portion 124 to the central processing unit 100.
The driving portion 101 is made up of a horizontal motor 102 that horizontally rotates the instrument body 52, a vertical motor 106 that vertically rotates the telescope 54, and a horizontal driving portion 104 and a vertical driving portion 108 that supply driving current to the motors 102 and 106, respectively. The measuring portion 109 is made up of a horizontal encoder 111 that horizontally rotates together with the instrument body 52, a vertical encoder 110 that vertically rotates together with the telescope 54, a horizontal angle measuring portion 112 and a vertical angle measuring portion 116 that read the rotation angles of the encoders 111 and 110, respectively, and a distance measuring portion (not shown). The distance measuring portion may be either a pulse-type distance measuring system or a phase-difference-type distance measuring system.
The surveying instrument 50 additionally includes an automatic collimator that automatically directs the optical axis (collimation axis) of the telescope 54 toward the reflecting prism 62. The automatic collimator is made up of the central processing unit 100, the collimation light emitting portion 118, the collimation light receiver 120, and the driving portion 101. The automatic collimator emits collimation light 58 from the collimation light emitting portion 118, then receives the collimation light 58 reflected and returned from the reflecting prism 62 by means of the collimation light receiver 120, then determines the direction of the reflecting prism 62 by means of the central processing unit 100, and controls the driving portion 101 so that the optical axis of the telescope 54 can be directed toward the reflecting prism 62. The optical axis of the automatic collimator and the optical axis of the optical system of the distance measuring portion are coaxial.
The surveying instrument 50 additionally has a collimation preparing means for pre-directing the telescope 54 toward the target 60 before starting the automatic collimator. The collimation preparing means is made up of the direction detector 56, the wireless device 70, the driving portion 101, and the central processing unit 100 connected thereto. Based on an output signal emitted from the direction detector 56, the collimation preparing means directs the telescope 54 toward the guide light transmitter 66, and starts automatic collimation when it is determined that the telescope 54 has been directed approximately toward the target 60.
On the other hand, the target 60 has a central processing unit 80 connected to the guide light transmitter 66 and to the wireless device 72, in addition to the reflecting prism 62, the guide light transmitter 66, and the wireless device 72. An operating/inputting portion 82 that inputs various commands and data and a display 84 that displays a state of the target 60 or a state of the surveying instrument 50 are connected to the central processing unit 80.
Referring now to FIG. 10, a description will be given of a measuring process in the survey system.
When the survey system is started, the process proceeds to step S1, at which the target 60 emits guide light 64 from the guide light transmitter 66. The process then proceeds to step S2, at which a horizontal rotation command signal to horizontally rotate the instrument body 52 is transmitted to the surveying instrument 50. The surveying instrument 50 then receives the horizontal rotation command signal at step S101. The process then proceeds to step S102, at which a horizontal rotation starting notice is transmitted to the target 60. The target 60 confirms the horizontal rotation of the instrument body 52 at step S3, and thereby knows that the surveying instrument 50 has started the horizontal search of the guide light 64.
On the other hand, on the side of the surveying instrument 50, the process proceeds to step S103, at which the instrument body 52 is horizontally rotated. The process then proceeds to step S104, at which the horizontal direction of the target 60 is detected by receiving the guide light 64. If the guide light 64 cannot be received in predetermined time here, the process proceeds to step S105, at which an error notice is transmitted to the target 60. After the target 60 receives the error notice at step S4, the process proceeds to step S5, at which the target 60 causes the display 84 to display a horizontal detection error, and is stopped.
If the guide light 64 is received at step S104, the process proceeds to step S106, at which the horizontal position of the telescope 54 is adjusted toward the guide light transmitter 66, and the horizontal rotation of the instrument body 52 is stopped. The process then proceeds to step S107, at which a guide light OFF command is transmitted to the target 60. When the guide light OFF command is received at step S6, the target 60 recognizes that the horizontal search of the guide light transmitter 66 has been completed in the surveying instrument 50, and therefore the process proceeds to step S7, at which the guide light 64 is turned off. The process then proceeds to step S8, at which the guide light OFF notice is transmitted to the surveying instrument 50.
If the surveying instrument 50 confirms the guide light OFF notice at step S108, the process proceeds to step S109, at which collimation light 58 is emitted. The process then proceeds to step S110, at which the notice of starting the vertical rotation of the telescope 54 is transmitted to the target 60. The vertical rotation notice is confirmed at step S9, and thereby the target 60 recognizes that the surveying instrument 50 has started the vertical search of the target 60. On the other hand, on the side of the surveying instrument, the process proceeds to step S111, at which the telescope 54 is vertically rotated, and the vertical search of the target 60 is continued.
The process then proceeds to step S112, at which the surveying instrument 50 emits collimation light 58, and the collimation light 58 reflected and returned from the target 60 is received, whereby the vertical direction of the target 60 is detected. If the collimation light 58 cannot be received here, the process returns to step S101, at which a flow procedure is repeated, or the process proceeds to step S113, at which an error notice is transmitted to the target 60. If the target 60 confirms the error notice at step S10, the process proceeds to step S11, at which the target 60 causes the display 84 to display a vertical direction detecting error, and is stopped.
If the collimation light 58 is received at step S112, the process proceeds to step S114, at which the telescope 54 is adjusted at the vertical position of the target 60, and the telescope 54 is stopped. The process then proceeds to step S115, at which a collimating operation is started, and a notice to the effect that a collimating operation is being carried out is transmitted to the target 60. The target 60 confirms that a collimating operation is being carried out at step S12, whereby the surveying instrument 50 recognizes that the automatic collimator has been started. On the other hand, on the side of the surveying instrument 50, the process proceeds to step S116, at which the automatic collimating operation is continued.
If the collimating operation cannot be satisfactorily collimated out at step S116, the process proceeds to step S117, at which an error notice is transmitted to the target 60. If the target 60 confirms the error notice at step S13, the process proceeds to step S14, at which the target 60 causes the display 84 to display a collimation error, and is stopped. If the collimating operation is satisfactorily collimated out at step S116, the process proceeds to step S118, at which a collimation completion notice is transmitted to the target 60. As a result, the target 60 recognizes that automatic collimation has been completed in the surveying instrument 50 at step S15.
The process then proceeds to step S119, at which the surveying instrument 50 performs distance and angle measuring operations. The process then proceeds to step S120, at which measured distance and angle values are transmitted to the target 60. The target 60 confirms the measured distance and angle values at step S16, and then causes the display 84 to display the survey results of the measured distance and angle values and other results, and the survey is ended.
In a case in which the errors are displayed on the display 84, and operations are stopped by these errors, it is recommended to remove the causes of the errors and then re-start the operation of the survey system.
According to this survey system, since the fan-shaped beam of guide light 64 is emitted from the side of the target 60 while scanning, the guide light 64 having adequate intensity can be emitted to a large range with less electric power, and the surveying instrument 50 can swiftly find the target 60, so that time required to complete automatic collimation can be shortened.
[Patent Document 1] Japanese Patent Application No. 2004-023614